Flooding dynamics within an Amazonian floodplain: water circulation patterns and inundation duration

Hydrodynamic

Study of the variability in suspended sediment discharge at Manacapuru, Amazon River, Brazil

The Manacapuru hydrometric gauge station has been used for more than 30 years by the Brazilian National hydrometric network to provide data on the Solimões-Amazon River. At this place, the Solimões river average water discharge is about 103,000 m³ s-1, the mean width is 3,000 m and the mean depth is 20 m. The gauge station record represents the whole upstream contribution of the total suspended solids (TSS) from the Solimões basin, whose total area is approximately 2 x 106 km2, representing a runoff of 0.48 m³ s-1 km-2. TSS annual flow is approximately 400 x 106 t. The systematic TSS sampling procedures traditionally used at the Brazilian hydrometric network has limitations, some of them being related to local effects affecting the TSS flow. This article aims to study the local variability of TSS flow at Manacapuru station. The study was conducted in the scope of MESASOL and PIATAM IV projects, whose objectives are precisely to consider alternative methods for TSS flow assessment in the Amazon basin. It was identified that local geologic-geomorphologic features are related with the TSS flux spatial variability at the vicinity of the Manacapuru section. This results induce a new interpretation to the general sediment flux for the Solimões river basin, were local flux can’t be see as a total flux from the hole up-stream river basin

Altimetry for the future: Building on 25 years of progress

In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in Ponta Delgada, Portugal, 25 Years of Progress in Radar Altimetry. On this latter occasion it was decided to collect contributions of scientists, engineers and managers involved in the worldwide altimetry community to depict the state of altimetry and propose recommendations for the altimetry of the future. This paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. Recommendations provided are fundamental for optimizing further scientific and operational advances of oceanographic observations by altimetry, including requirements for spatial and temporal resolution of altimetric measurements, their accuracy and continuity. There are also new challenges and new openings mentioned in the paper that are particularly crucial for observations at higher latitudes, for coastal oceanography, for cryospheric studies and for hydrology. The paper starts with a general introduction followed by a section on Earth System Science including Ocean Dynamics, Sea Level, the Coastal Ocean, Hydrology, the Cryosphere and Polar Oceans and the ‘‘Green” Ocean, extending the frontier from biogeochemistry to marine ecology. Applications are described in a subsequent section, which covers Operational Oceanography, Weather, Hurricane Wave and Wind Forecasting, Climate projection. Instruments’ development and satellite missions’ evolutions are described in a fourth section. A fifth section covers the key observations that altimeters provide and their potential complements, from other Earth observation measurements to in situ data. Section 6 identifies the data and methods and provides some accuracy and resolution requirements for the wet tropospheric correction, the orbit and other geodetic requirements, the Mean Sea Surface, Geoid and Mean Dynamic Topography, Calibration and Validation, data accuracy, data access and handling (including the DUACS system). Section 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). Section 8 reviews the programmatic issues followed by a conclusion

Altimetry for the future: building on 25 years of progress

In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in Ponta Delgada, Portugal, 25 Years of Progress in Radar Altimetry. On this latter occasion it was decided to collect contributions of scientists, engineers and managers involved in the worldwide altimetry community to depict the state of altimetry and propose recommendations for the altimetry of the future. This paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. Recommendations provided are fundamental for optimizing further scientific and operational advances of oceanographic observations by altimetry, including requirements for spatial and temporal resolution of altimetric measurements, their accuracy and continuity. There are also new challenges and new openings mentioned in the paper that are particularly crucial for observations at higher latitudes, for coastal oceanography, for cryospheric studies and for hydrology. The paper starts with a general introduction followed by a section on Earth System Science including Ocean Dynamics, Sea Level, the Coastal Ocean, Hydrology, the Cryosphere and Polar Oceans and the “Green” Ocean, extending the frontier from biogeochemistry to marine ecology. Applications are described in a subsequent section, which covers Operational Oceanography, Weather, Hurricane Wave and Wind Forecasting, Climate projection. Instruments’ development and satellite missions’ evolutions are described in a fourth section. A fifth section covers the key observations that altimeters provide and their potential complements, from other Earth observation measurements to in situ data. Section 6 identifies the data and methods and provides some accuracy and resolution requirements for the wet tropospheric correction, the orbit and other geodetic requirements, the Mean Sea Surface, Geoid and Mean Dynamic Topography, Calibration and Validation, data accuracy, data access and handling (including the DUACS system). Section 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). Section 8 reviews the programmatic issues followed by a conclusion

Recherche methodologique sur le traitement d'images de teledetection aerienne, basee sur l'analyse prealable des formations superficielles avec leur couverture vegetale : etude d'un secteur de lande sur schistes en Bretagne centrale

SIGLECNRS T 60231 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Rating curve estimation using Envisat virtual stations on the main Orinoco river

Rating curve estimation (height-stream relation) made by hydrometric stations representing cross-sections of a river is one of hydrometrics’ fundamental tasks due to the fact that it leads to deducing a river’s average daily flow on that particular section. This information is fundamental in any attempt at hydrological modelling. However, the number of hydrological control stations monitoring large hydrological basins has been reduced worldwide. Space hydrology studies during the last five years have shown that satellite radar altimetry means that hydrological monitoring networks’ available information can be densified due to the introduction of so-called virtual stations and the joint use of such information along with in-situ measured flow records for estimating expenditure curves at these stations. This study presents the rating curves for 4 Envisat virtual stations located on the main stream of the Orinoco River. Virtual stations’ flows were estimated by using the Muskingum- Cunge 1D model. There was less than 1% error between measured and estimated flows. The methodology led to reducing average zero flow depth; in this case, it led to depths ranging from 11 to 20 meters being found along the 130 km of the Orinoco River represented by the virtual stations being considered.La estimación de curvas de gasto (relación altura-caudal) para las estaciones hidrométricas que representan las secciones transversales de un río es una de las tareas fundamentales de la hidrometría, ya que estas permiten, entre otras cosas, la deducción de los caudales medios diarios del río sobre esas secciones. Dicha información es fundamental para cualquier tentativa de modelación hidrológica; sin embargo, la disminución de estaciones de control para el monitorio hidrológico sobre grandes cuencas es patente a nivel mundial. Desde hace cinco años diferentes estudios en hidrología espacial han demostrado que la altimetría radar por satélite permite densificar la información disponible sobre las redes de monitoreo hidrológico gracias a la introducción de las llamadas estaciones virtuales y que la utilización conjunta de esta información, junto con registros de caudales medidos in situ implican la estimación de curvas de gasto en las nombradas estaciones. Este estudio presenta las curvas de gasto deducidas para cuatro estaciones virtuales Envisat sobre el cauce principal del río Orinoco. Los caudales en las estaciones virtuales fueron estimados aplicando el modelo 1D de Muskingum- Cunge. Los errores entre caudales medidos y estimados son inferiores al 1%. Se ha aplicado una metodología que permite deducir la profundidad media del flujo cero, la cual en este caso nos ha llevado a encontrar profundidades que varían entre once y veinte metros a lo largo de los 130 km del río Orinoco representados por las estaciones virtuales consideradas

Study of the variability in suspended sediment discharge at Manacapuru, Amazon River, Brazil

The Manacapuru hydrometric gauge station has been used for more than 30 years by the Brazilian National hydrometric network to provide data on the Solimões- Amazon River. At this place, the Solimões river average water discharge is about 103,000 m³ s-1, the mean width is 3,000 m and the mean depth is 20 m. The gauge station record represents the whole upstream contribution of the total suspended solids (TSS) from the Solimões basin, whose total area is approximately 2 x 10(6) km², representing a runoff of 0.48 m³ s-1 km-2. TSS annual flow is approximately 400 x 10(6) t. The systematic TSS sampling procedures traditionally used at the Brazilian hydrometric network has limitations, some of them being related to local effects affecting the TSS flow. This article aims to study the local variability of TSS flow at Manacapuru station. The study was conducted in the scope of MESASOL and PIATAM IV projects, whose objectives are precisely to consider alternative methods for TSS flow assessment in the Amazon basin. It was identified that local geologic-geomorphologic features are related with the TSS flux spatial variability at the vicinity of the Manacapuru section. This results induce a new interpretation to the general sediment flux for the Solimões river basin, were local flux can’t be see as a total flux from the hole up-stream river basin.A estação hidrométrica de Manacapuru é uma localidade utilizada há mais de 30 anos na rede hidrométrica brasileira. Esta estação, cuja seção transversal sobre o Rio Solimões, tem em média: 3000 metros de largura e 20 metros de profundidade, controla praticamente a totalidade das contribuições das MES (Material Em Suspensão) oriundos da bacia do Rio Solimões, cuja área total é de aproximadamente 2 milhões de km², a descarga líquida média é de 103.000 m³ s-1, ou 48 l s-1 km-2. O fluxo médio total anual de MES é de aproximadamente 400 x 10(6) toneladas. A sistemática tradicional de amostragem de material em suspensão (MES) tem limitações quanto a avaliar efeitos locais nesse fluxo. O presente artigo pretende apresentar alguns fenômenos locais que de algum modo interferem no fluxo local de MES do Rio Solimões em Manacapuru. O estudo foi realizado no escopo do Projeto MESASOL e PIATAM IV, projetos que têm investigado métodos alternativos de avaliação do fluxo de MES na bacia Amazônica na busca de melhorar a precisão e diminuir os custos operacionais na aquisição de dados hidrológicos. Os resultados indicam que as características geológicas e geomorfológicas locais influenciam no fluxo de MES, com grande variabilidade espacial em superfície na vizinhança da seção de Manacapuru. Isso resulta induzir uma nova interpretação para o fluxo de sedimentos na bacia do rio Solimões, onde os fluxos locais não podem ser diretamente interpretados como da bacia de montante

Predominance of agropastoral production systems in the state of Rondônia, Brazilian Amazonia, between 2004 and 2014, link to GIS file

This file contains a regular grid of 10 x10 km with the identification of the predominant agropastoral production systems at the cellular level in Rondônia State, in the Brazilian Amazon. To perform this classification, a decision tree was used, applied in landscape metrics based on deforestation (PRODES data), land use/cover (TerraClass data) and distance matrices to landscape elements of regional infrastructure of roads and agricultural manufacture plants of local production. The mean values of such metrics retrieved from land use/cover data were used in a decision tree classification method allowing the identification of seven classes of agricultural production systems plus two other classes of forest domain. Cells were classified in Forest Domain (FD); Initial Front (IF), Coexistence Area (CA); Dominant Agriculture (DA); Strict Agriculture (SA); Intensified Beef (IB); Intensified Beef Milk (IBM); Not Intensified Beef (NIB) or Not Intensified Beef Milk (NIBM)

Hydro-climatology study of the Ogooué River basin using hydrological modeling and satellite altimetry

International audienceHydrological models are important tools for the simulation of water storage and hydrological fluxes in large basins and complex river systems. The hydrological models can compensate the lack of observed data in ungauged basins. In this study, the hydrological model of large basins MGB (for Model of Large Basins in Portuguese) is used to evaluate the hydrological processes of the Ogooué River Basin (ORB), which has been mostly unmonitored for about three decades. Simulations were carried out over an 18-year period from 1998 to 2015 using TRMM 3B42 daily rainfall data from the Tropical Rainfall Measurement Mission (TRMM) as forcing and in situ and altimetry-based river discharges from Envisat, Saral Altika and Jason-2 for calibration and validation. The results of the model were in good agreement with the flows measured at stations upstream and downstream of the Ogooué basin (Nash-Sutcliffe Efficiency (NSE) > 0.56 for all calibration gauges). The MGB model efficiently describes the seasonal and interannual variations of the flow in the Ogooué River and its major tributaries which were found to be highly correlated to the rainfall (r ranging from 0.72 to 0.90 and 0.56 to 0.87 at seasonal and interannual time-scales respectively). Interannual variations of precipitation and river discharge of the ORB are linked to the El Niño Southern Oscillation (ENSO) in the tropical eastern Pacific Ocean and southeastern tropical Atlantic Niño. Also, the Ogooué River discharge was found to be strongly correlated with Sea Surface Temperature (SST) at annual and semi-annual time-scales